I have ESET Nod 32 Internet Security running and it says I have a virus in my memory and it's unable to delete it.

My programs are constantly crashing and Im using around 3 of 4 GB of memory.

How can I fix this?

Try the follwoing to troubleshoot your problem.

1. Try BitDefender antivitus according my practical experience from the past 2 years its the best Anti-virus Software and will clean your system download the trial version (www.bitdefender.com)
2. Scan your system in Safe Mode
3. Try Changing the memory (IF its possible for you)
4. Take a backup of your files and format your windows make sure you remove all drives and create them again.

NOTE: Scan it with your antivirus before you copy data back to system.

* Double-click mbam-setup.exe and follow the prompts to install the program.
* At the end, be sure to checkmark the Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
* If an update is found, it will download and install the latest version.
* Once the program has loaded, select Perform full scan, then click Scan.
* Make sure all applications including browsers are closed during the scan and you are preferably not in safe mode
* When the scan is complete, click OK, then Show Results to view the results.
* Be sure that everything is checked, and click Remove Selected.
* When completed, a log will open in Notepad, Save the Logfile.
* Immediately Reboot he computer

*Now download TrendMicro HijackThis
*Install it, Run it and click on 'Run a scan and save a logfile'
*After the scan you will get a notepad window with the scan results, Save it.
* Post both the MBAM and HJT logs back here.